Railway-traffic-controlling apparatus



March 24. 1925. 1,531,115

' R. A. MGCANN RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Oct. 4 1924INVENTORI Q. Q; m BY K Ak n. ATTORNEY Patented Mar. 24, 1925.

UNITED STATES PATENT OFFICE.

RONALD A. MCCANN, OF SWISSVALE, PENNSYLVANIA, ASSIGNOR TO THE UNIONSWITCH 8Z2 SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OFPENNSYLVANIA.

RAILWAY-TRAFFIC-CONTROLLING APPARATUS.

Application filed October 4, 1924. Serial No. 741,769.

To all whom it may concern.

Be it known that I, RONALD A. MGCANN, a citizen of the United States,residing at Swissvale, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements inRailway-Traffic-Controlling Apparatus, of which the following is aspecification.

My invention relates to railway trafiic controlling apparatus, andparticularly to apparatus of the type wherein governing mechanism on acar or train is controlled by energy received from the trackway.

I will describe one form of apparatus embodying my invention, and willthen point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic view showing one form ofapparatus embodying my invention.

Referring to the drawing, the reference characters 1 and 1 designate thetrack rails of a railway along which traffic moves in the directionindicated by the arrow. These rails are divided by insulated joints 2 toform a plurality of track sections, of which only three completesections A-B, BC, and C-D, are shown in the drawing.

Located adjacent the entrance end of each section is a signal designatedby the reference character S, with an exponent corresponding to thelocation. Each of the signals, as here shown, is of the semaphore typeadapted to indicate stop, caution, and proceed. The circuit forcontrolling these signals are omitted from the drawing for the reasonthat they form no part of my present invention. It is sufficient to saythat each signal indicates stop when the associated section is occupied,caution when the associated section is unoccupied and the section nextin advance is occupied, and proceed when the associated section and thesection next in advance are both unoccupied.

Each section is provided with a track relay designated by the referencecharacter E with an exponent corresponding to the location. Each trackrelay comprises a track winding 3 connected across the rails adjacentthe entrance end of the corresponding section, and a local winding 4:,which is supplied with current in the manner hereinafter explained.

Alternating signaling current is normally supplied to the rails of eachsection by a transformer designated by the reference character H, withan exponent corresponding to the location. The secondary of eachtransformer H is connected across the rails adjacent the exit end of theassociated section through a current-limiting impedance 16. Referringparticularly to transformer H the circuit for the primary of thistransformer is from the secondary 6 of a line transformer M through wire24:, back contact 11 of a line relay F, wire 25, primary of transformerH and common wire 0, to the secondary 6 of transformer M 'When thisprimary circuit is closed, that is, when line relay F is de-energized,current is supplied to the local winding 4 of track relay E by a circuitwhich passes from the secondary 6 of transformer M through wires 24: and26 back point of contact 13 of relay F wire 28, local winding 4; oftrack relay E and common wire 0 to secondary 6 of transformer M Theprimary 8 of transformer M is connected with a transmission line L whichis constantly supplied with alternating signaling current by a generatorG It will be seen from the foregoing, that when relay F is de-energized,alternating signaling current is supplied to the rails of section GD,and also to the local winding 4 of track relay E so that this relay isenergized.

hen a train enters section (3-D it will. of course, de-energize trackrelay E and if track relay E for section B-C is then energized, linerelay F will become energized by a circuit which passes from secondary 7of transformer M through wire 17, back contact 15 of track relay E wire18, front contact 14: of track relay E wire 19, relay F and common wire0 to secondary 7 of transformer M The energization of line relay F willopen the circuit hereinbefore traced for the primary of transformer Hand will close a circuit for the primary of a track transformer J whichcircuit is from secondary 9 of a transformer K", through wires 20 and21, circuit controller N operated by signal S, wire 22, contact 12 ofrelay F wire 28, primary of transformer J and common wire 0 to secondary9 of transformer K If signal S indicates caution or proceed,

circuit controller N Will be closed, so that current from transformed Kwill be supplied to the primary of transformer J. The secondary oftransformer J is connected across the rails of section CD, through acurrent-limiting impedance 16. The primary 10 of transformer K isconnected with a transmission line L which is constantly supplied withalt eruating train governing current by a generator G It will be seen,therefore, that while section CD is occupied by a train, if section BCis unoccupied, the source of signaling current will be disconnected fromthe rails of section CD and train governing current from generator Gwill be supplied to the rails of this section. The energization of linerelay F will also open the circuit previously traced for local winding 4of track relay E and will close a new circuit for this winding, whichcircuit passes from the secondary 9 of transformer K through wires 20and 27, front point of contact 13 of line relay F wire 28, winding 4 ofrelay E and common wire 0 to the secondary 9 of transformer K It followsthat when section CD is occupied and section BC is unoccupied,alternating train-governing current is supplied to the rails of sectionOD and also to local winding 4 of track relay E for this section.

The alternating currents delivered by the two generators G and G differin frequency. As an example, the frequency of the signaling generator Gmay be 25 cycles per second, and the frequency of the traingoverninggenerator G may be 100 cycles per second.

The apparatus and circuits associated with each section are the same asthe apparatus and circuits associated with section CD and describedhercinbefore.

The trackway apparatus shown herein is intended for co-operation withtrain-carried governing mechanism so arranged that when the trainoccupies a section which is supplied with train-governing current aproceed indication will be given aboard the train, but that when thetrain occupies a section which is supplied with signaling currentinstead of train governing current a stop indication will be givenaboard the train.

As shown in the drawing, section A-B is occupied by a train V, so thattrack relay E is de-energized and signal S inclicates stop. Inasmuch astrack relay E is energized, line relay F is also energized, so thattrain-governing current is supplied to the rails of section AB, and so aproceed indication is given on train V.

I will now assume that a train enters section CD, thereby de-energizingtrack relay E and causing line relay F to bei i i come energized}Train-governing current will then be supplied to the rails of sectionB-C andj also to local winding lof track relay E As the front end. ofthe train enters section BC it; will de-energize track relay E therebytie-energizing line relay F and line relay F in turn will restorecurrent of the signaling frequency to the rails of section C-D and alsoto the local winding at of track relay E lVhen the rear end of the trainpasses out of section CD, track relay E will again become energized andso the apparatus associated with this section will be restored to itsnormal condition. The de-energization of track relay E due to the trainentering section BC will not cause line relay F to become energized,because the circuit for this line relay is open at contact 14 of trackrelay E The rails of section BO will, therefore, continue to be suppliedwith current of signaling frequency, and so a stop indication will begiven aboard the train informing the engineer that section A-B isoccupied.

I will now assume that a train enters section CD, that the train comesto a stop in this section and then backs out of the section. Vhile thetrain is in section CD track relay E is, of course, de-energized, andline relay F is energized, so that traingoverning current is supplied tothe rails and also to winding 4 of track relay E \Vhen the train backsout of the section, current of train-governing frequency will besupplied to both windings 3 and 4t of track relay E so that this relaywill then become energized. The opening of the back contact 15 of relayE will then open the circuit for line relay F which latter relay willthereupon become tie-energized, and so will restore current of thesignaling frequency to both windings of relay E It will be noted thatunder normal conditions, that is, when all track sections areunoccupied, the train-governing transformers K are entirely disconnectedfrom the track rails, whereas the secondary 6 of each signalingtransformer M is connected with the track rails. It will furthermore benoted that when a section is occupied, the second ary 6 of theassociated signaling transformer M is entirely disconnected from thetrack rails, and secouda ry t) of the associated traingoverningtransformer K is connected with the track rails. It follows, therefore,that there is no opportunity for train-governing current to flow fromthe rails of an unoccupied section into the transmission line L for thesignaling current, and from there through transformer M and into therails of the occupied section. In other words, there is no opportunityfor train-governing current to get into the rails of an occupied sectionthrough the transmission line system llt) and thereby cause a falseproceed indication on a train.

Although I have herein shown and described only one form of apparatusembodying my invention, it is understood that various changes andmodifications may be made therein within. the scope of the appendedclaims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claims is:

1. In combination, a railway track divided into sections, a track relayfor each section having a track winding connected with the rails of thesection and a/local winding, a line relay for each section, a circuitfor each line relay including a back contact of the track relay for thesame section and a front contact of the track relay for the section nextin advance, and means for each section for supplying current of onefrequency to the track rails and to the track relay local winding whensaid line relay is de-energized and for supplying current of anotherfrequency to the track rails and to the track relay local winding whensaid line relay is energized.

2. In combination, a railway track divided into sections, a track relayfen each section having a track winding cqnncted with the rails of thesection and acl'ocal winding, a line relay for each section, a circuitfor each line relay including a back contact of the track relay for thesame section and a front contact of the track relay for the section nextin advance, two transmission lines extending along said railway trackand carrying currents of different frequencies, and means for eachsection for supplying current from one transmission line or the other tothe track rails and the local winding of the track relay according assaid line relay is de-energized or energized.

3. In combination, a railway track divided into sections, a track relayfor each section, a line relay for each section, a circuit for each linerelay including a back contact of the track relay for the same sectionand a front contact of the track relay for the section next in advance,andineans for each section for supplying curr cnt of one frequency oranother to the track rails accord ing as the line relay for the section.is deenergized or energized.

t. In combination, a railway track divided into sections. a track relayfor each section, a line relay for each section, a circuit for each linerelay including a back contact of the track relay for the same sectionand a front contact of the track relay for the section next in advance,two transmission lines extending along said railway track and carryingcurrents of difierent freque cies, and means for each section for supying current from one transmission line or the other to. the track railsof the section according as the line relay for the section isde-energized or energized.

5. In combination, a railway track divided into sections, a track relayfor each section having a track winding connected with the rails of thesection and a local winding, a line relay for eachsection, means forenergizing each. line relay when the track relay for the same section isde-energized and the section next in advance is unoccupied, and meansfor each section for supplying current of one frequency to the trackrails and to the track relay local \vi11di11 "'wl1en said line relay istie-energized and r supplying current of another frequenc to the trackrails and to the track relay local winding when said line relay isenergized.

6. In combination, a railway track divided into sections, a track relayfor each section having a track winding connected with the rails of thesection and a local winding, a line relay for each section, means forenergizing each line relay when the track relay for the same section isde-energized and the section next in advance is unoccupied, twotransmission lines extending along said railway track and carryingcurrents of diiferent frequencies, and means for each section forsupplying current from one transmission line or the other to the trackrails and the local winding of the track relay according as said linerelay is de-energized or energized.

7. In combination, a railway track divided into sections, a track relayfor each section, a line relay for each section, means for energizingeach line relay when the track relay for the same section isde-energized and the section next in advance is unoccupied, twotransmission lines extending along said railway ,track and carryingcurrents of different frequencies, and means for each section forsupplying current from one transmission line or the other to the trackrails of the section according as the line relay for the section isenergized or deenergized.

8. In combination, a railway track divided into sections, means fornormally supplying current of one frequency to the rails of eachsection, and means operating to discontinue the supply of said currentand to supply current of a. diflierent :t're'quency to the rails of asection when. the section is occupied by a. train and traffic conditionsin advance are safe.

9. In combination, a railway track divided into sections, twotransmission lines extending along said track and carrying currents ofdifferent frequencies, means for normally supplying current from one ofsaid lines to the track rails of each section, and means fordiscontinuing the supply of current from said one line and supplyingcurrent from the other line to the rails of each section when thesection is occupied by a train and trai'iic conditions in advance aresafe.

10. In combination, a railway track divided into sections, a track relayfor each sec; tion having a track winding connected with the rails ofthe section and a local winding, a normally de-energized line relay foreach section, means for energizing each line relay wien the associatedsection is occupied by a train and traffic conditions in advance aresafe, and means for each section for supplying current of one frequencyto the track rails and to the track relay local winding when said linerelay is de-energized and for supplying current of another frequency tothe track rails and to the track relay local winding when said linerelay is energized.

11. In combination, a railway track divided into sections, a track relayfor each section having a track winding connected with the rails of thesection and a local Winding, a normally de-energized line relay for eachsection, means for energizingeach line relay when the associated sectionis occupied by a train and traflic conditions in advance are safe, twotransmission lines extending along said railway track and carryingcurrents of different frequencies, and means for each section forsupplying current from one transmission line or the other to the trackrails and the local winding of the track relay according as said linerelay is deenergized or energized.

In testimony whereof I aflix my signature.

RONALD A. MoCANN.

